1. Field of the Invention
In general, this present invention pertains to the retrieval of natural resources from the seabed. More particularly, it is directed to a novel and improved ocean floor surficial dredging apparatus which will retrieve simply and economically particulate resources from on and below the seabed surface, especially in deep environments.
2. Description of Prior Art
The ocean and seabeds possess enormous deposits of mineral wealth which is particularly useful for a wide variety of industrial purposes. Generaly speaking, a substantial number of drawbacks are associated with the ordinary retrieval techniques heretofore applied in retrieving minerals. Foremost among these difficulties, from a technological standpoint, is the fact that the mining operations must be conducted in a marine environment. Such environment, of course, presents a significant number of inherently unique conditions, such as exceedingly high water pressure, varying seabed compositions and topographical environments, and the adverse effects of sea water, as is believed evident. These conditions are usually not encountered in the vast majority of present day mining situations. Such, of the previously mentioned disadvantages are further compounded in those circumstances where the mining to be carried out in deep sea situations.
It should also be pointed out that the method of exploitation, the character of the mineral deposits, and the specific environment under which the deposits are to be retrieved define important considerations in ascertaining whether or not a particular deposit can be successfully and economically extracted. Heretofore known devices have been unable to economically retrieve the particulate minerals.
One general category of the multitude of minerals distributed throughout the ocean and ocean floor is found in the form of particular types of pelagic sedimentation. Such types take a number of physical forms including grains, slabs, and other important forms of agglomerated colloidal particles. For instance, it has been discovered that some of these forms are typically dispersed on the bottom in a monolayer and ordinarily average from 0.5, to 2.50 cm. in diameter. Furthermore, such dispersions have been located at exceedingly deep depths, some over 5,000 meters. It can be readily appreciated that at such depths there is a tremendous amount of water pressure to contend with not to mention the various types of seabed compositions and ocean currents. As a result of the foregoing, successful mining has been substantially hindered.
In general known attempts to retrieve such minerals have not been successful, particularly from an economic standpoint. Approaches employed for purposes of retrieving minerals; through the application of drag dredge devices, or bucket dredge devices. Either approach is severely limited by reason of the exceedingly long cables necessary to dredge the ocean bottom. Moreover, the power machinery including winches and booms are placed under severe fatigue loading conditions requiring constant maintenance not to mention the expensive cost of operation.
Another manner of retrieving marine sediment maybe achieved through utilization of free fall coring apparatuses. Such known coring devices while suitable for some certain purposes are not especially suitable for automatically, selectively and exclusively retrieving particulate sediment of predetermined sizes. Moreover, they are, in general, characterized by relatively numerous and costly components, not to mention complicated construction and burdensome weight release mechanisms. It will of course be recognized that by virtue of such apparatuses having relatively large numbers of components there also exists a tendency for them to fail or otherwise function unsatisfactorially. This is especially so in situations wherein the several moving and mechanically interrelated components are subjected to exceedingly high water pressure and must extract minerals on or embedded in the sea floor. Accordingly, in view of the foregoing numerous drawbacks known methods and apparatuses utilizing in the field of ocean mining to retrieve particulate materials from the seabed have been unable to do so in a manner which is relatively economical, effective, and reliable in operation.